In electrophotographic image forming apparatuses (hereinafter also referred to as “electrophotographic apparatuses”), such as a copying machine and a printer, electrophotographic apparatuses capable of forming high-quality color images have been placed on the market. In such electrophotographic apparatuses, as one method for forming a color image on a recording medium, such as paper, for example, the following method may be mentioned. Toner images are developed using individual colors and are then sequentially transferred to an intermediate transfer member, so that color toner images are formed on the intermediate transfer member. Subsequently, the color toner images formed on the intermediate transfer member are again collectively transferred to a recording medium, thereby obtaining a recording medium on which the color toner images are formed.
As the intermediate transfer member used in this case, a belt which is formed of a thermosetting resin, such as a polyimide resin or a poly(amide imide) resin, and carbon black dispersed therein has been known. Such intermediate transfer member as described above may be obtained by forming a coating film from a dispersion liquid formed of a resin varnish or a poly(amic acid) vanish, which is a resin precursor solution, and carbon black dispersed therein, followed by firing.
In addition, in recent years, an intermediate transfer member manufactured by melt extrusion molding using a resin composition formed of a thermoplastic resin and carbon black dispersed therein has been progressively investigated. Since melt extrusion molding can be performed, the intermediate transfer member formed from a thermoplastic resin has advantages in comparison to the above intermediate transfer member formed from a thermosetting plastic in view of easy molding, reduction in environmental load, reduction in cost, and the like.
In spite of the advantages described above, in electrophotographic apparatuses that are required to have high speed operation and high durability, an intermediate transfer member simply formed using a thermoplastic resin has not sufficiently satisfied the transfer performance in some cases. Accordingly, in order to improve the transfer performance, various treatments on the surface of the intermediate transfer member have been attempted. In order to reduce the adhesion of a developer to the surface of the intermediate transfer member, PTLs 1 and 2 have proposed an intermediate transfer member having transfer efficiency improved by applying a fluorine compound having hydrophobic and lipophobic properties to a surface of the intermediate transfer member.
However, in the case in which the intermediate transfer member having a surface applied with a fluorine compound is repeatedly used for the formation of electrophotographic images for a long time, the transfer efficiency of toner from the intermediate transfer member to recording media gradually decreases, and in association with this decrease, the image quality transferred on the recording media may also be gradually degraded in some cases. Accordingly, research and development of an intermediate transfer member that, even if used for a long time, can retain superior transfer efficiency of toner has been desired.